Battery system

Abstract

The invention discloses a battery system, comprising: a collet device for bearing, connecting and fixing a battery pack, the outer side of the battery pack being fixedly connected with a skin assembly; the upper frame assembly is connected and fixed above the bottom support device and is used for bearing, connecting and fixing the high-voltage distribution box, the BMS low-voltage control box and the liquid cooling unit; the liquid cooling pipeline assembly is fixedly connected to the bottom support device through a pipe frame, one end of the liquid cooling pipeline assembly is connected with a cooling liquid inlet and a cooling liquid outlet of the liquid cooling unit, and the other end is connected with a cooling liquid inlet and a cooling liquid outlet of the battery pack; the charging seat is connected and fixed below the bottom support device; the high-voltage power wire harness is used for bearing the voltage and large current of the whole battery system; and the low-voltage communication wire harness is used for transmitting control signals to the BMS low-voltage control box and supplying power to other parts of the battery system. The overall frame height of the battery system can be effectively reduced, the overall weight of the battery system is reduced, the cost of the battery system is reduced, and the thermal management thermal insulation performance of the battery pack is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power batteries, and in particular relates to a battery system. Background Art

[0002] New energy power battery packs are one of the core components of electric vehicles. The battery system accounts for approximately 20-30% of the total vehicle weight and is also one of the components with the highest cost in vehicle production.

[0003] Relevant research shows that under constant speed driving conditions, if the weight of an electric vehicle is reduced by 10%, the vehicle's cruising range can be increased by about 5.5%; from the perspective of the battery system, due to the large limitations on the composition and size of battery cell materials, weight reduction must first be addressed from the structural design direction level, which is mainly reflected in the integration of battery systems, the integration of high and low voltage electrical components, the integration of boxes and liquid cooling plates, the integration of small modules into large modules, and the appropriate size structure of battery cells, which have become the focus of current research by new energy vehicle companies.

[0004] At present, the common solution for commercial vehicle battery system installation is to independently connect and fix multiple battery packs and battery frames. An independent support beam structure is set inside the battery frame, which increases the overall height of the battery frame and reduces the volume and weight energy density of the entire battery system. The main disadvantages of this solution are as follows:

[0005] 1) The higher the height of the entire battery system, the greater the risk to the safety of the system (the higher the overall center of gravity, the lower the stability of the vehicle);

[0006] 2) The heavy weight of the battery system will affect the vehicle's range, increase operating costs and reduce operating efficiency.

[0007] 3) The battery system is heavy and the procurement cost of parts is high;

[0008] 4) The assembly operation of the battery system is complex, with many types and quantities of parts, long manufacturing hours and low production efficiency;

[0009] 5) The main method of fixing the battery pack to the battery frame is to use hexagonal bolts directly welded to the frame with nuts, which has low safety and reliability. The main reason is that when the vehicle is running for a long time or in relatively complex road conditions, it is easy to cause the bolts to back-twist, thus affecting the safety and stability of the entire battery system.

[0010] 6) After the current battery pack is connected and fixed to the battery frame, there will be an assembly gap of about 30mm or more between the battery pack layers, which reduces the thermal management and insulation performance of the battery pack, thereby affecting the service life and operating costs of the entire battery system device. Summary of the Invention

[0011] The object of the present invention is to provide a battery system that can effectively reduce the overall frame height of the battery system, reduce the overall weight of the battery system, reduce the cost of the battery system, and improve the thermal management and insulation performance of the battery pack.

[0012] To achieve the above object, the present invention provides a battery system comprising:

[0013] The bottom support device is used to carry and connect the battery pack. The outer side of the battery pack is connected and fixed with the skin component through the skin bracket;

[0014] The upper frame assembly is connected and fixed above the bottom support device, and is used to carry and connect the high-voltage distribution box, BMS low-voltage control box and liquid cooling unit. The liquid cooling unit is located on one side of the high-voltage distribution box, and the BMS low-voltage control box is located below the high-voltage distribution box.

[0015] The liquid cooling pipe assembly is fixed to the base device using a pipe rack, with one end connected to the coolant inlet and outlet of the liquid cooling unit, and the other end connected to the coolant inlet and outlet of the battery pack;

[0016] The charging base is connected and fixed under the bottom bracket device to provide power to the battery pack;

[0017] The high-voltage power harness is divided into two parts. One part is connected to the battery pack through the high-voltage distribution box, and the other part is connected to the vehicle control box through the high-voltage distribution box.

[0018] The low-voltage communication harness is divided into two parts. One part is used to connect the battery packs in the battery pack, and the other part is used to connect the low-voltage electrical equipment of the vehicle through the high-voltage distribution box and the BMS low-voltage control box to form a system communication circuit.

[0019] As a further solution of the present invention: the battery pack includes a plurality of stacked battery packs, the battery boxes of all the battery packs are stacked in sequence, the adjacent battery boxes are connected and fixed by fixing bolts, and a battery box cover is connected to the top battery box.

[0020] As a further solution of the present invention: the fixing bolt includes a threaded column, a bolt head is fixed at one end of the threaded column, and a locking nut is threadedly connected to the other end. Flat washer 1 is sleeved on the end of the threaded column close to the bolt head, flat washer 2 is sleeved on the end of the threaded column close to the locking nut, and a spring washer is sleeved on the threaded column between the bolt head and flat washer 1.

[0021] As a further solution of the present invention: sealing gaskets are connected to the sealing surfaces around the battery box.

[0022] As a further solution of the present invention: the bottom of the battery box is provided with a thermal insulation coating.

[0023] As a further solution of the present invention, the cooling pipes connecting the liquid cooling pipe assembly and the battery packs of the battery pack adopt a branch parallel connection method.

[0024] As a further solution of the present invention: a skin is provided for each battery pack in the skin assembly, and adjacent skins are pressed against each other and reinforced and fixed by bolts.

[0025] As a further solution of the present invention: the high-voltage power harness and the low-voltage communication harness are both connected and fixed with the base device using a fixing clip in combination with a cable tie.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The entire battery system consists of multiple stacked battery packs. The battery packs are fixed to each other using the side beams of the upper battery pack and the lower battery pack. The sealing solution adopts a conventional box body circumference sealing foam solution. The connection seal of the two battery packs can share a sealing foam, and the number of connecting and fixing bolts of the battery packs can be reduced by half. At the same time, the battery box cover between every two battery packs is eliminated. Only the top battery pack needs a battery box cover, and the electromagnetic box covers of other battery packs can be eliminated, which can effectively reduce the cost of the battery system.

[0028] The height of the overall battery system frame is reduced, and the battery packs are connected and fixed using a stacking solution. The fixed bracket of the battery system frame in the middle, that is, the crossbeam that fixes the battery pack, is eliminated. The more battery packs there are, the more significantly the height of the overall battery system is reduced, and the weight of the entire battery system is effectively reduced.

[0029] Each battery pack has an insulation coating on the bottom of the battery box, and the battery packs are fixed in a stacked manner, which reduces the height of the battery cells inside the battery pack to the upper battery pack box, reducing temperature instability caused by air flow. In addition, the insulation coating on the bottom of the battery box of the upper battery pack has a certain improvement in the internal insulation performance of the battery pack.

[0030] The battery pack stacking fixing bolt structure is designed as bolt head + spring washer + flat washer + flat washer + anti-loosening nut. Compared with the conventional design of bolt + wire thread sleeve structure, it has higher reliability and stronger connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the battery system of the present invention;

[0032] Figure 2 This is a schematic diagram of the connection structure between the bottom support device and the upper frame assembly of the battery system of the present invention;

[0033] Figure 3is a schematic diagram of a battery pack of a battery system of the present invention;

[0034] Figure 4 Schematic diagram of the battery box structure of the battery system of the present invention;

[0035] Figure 5 yes Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0036] Figure 6 It is a schematic diagram of the fixing bolt structure of the battery system of the present invention.

[0037] In the figure: 1. Bottom support device, 2. Skin bracket, 3. Skin assembly, 4. Battery pack, 5. Liquid cooling unit, 6. Upper frame assembly, 7. High-voltage distribution box, 8. BMS low-voltage control box, 9. Liquid cooling pipe assembly, 10. Low-voltage communication wiring harness, 11. Charging station, 12. High-voltage power wiring harness, 13. Fixing bolts, 14. Sealing foam;

[0038] 4.1. Battery box cover, 4.2. Battery box body;

[0039] 13.1. Bolt head, 13.2. Spring washer, 13.3. Flat washer 1, 13.4. Threaded column, 13.5. Flat washer 2, 13.6. Locknut. DETAILED DESCRIPTION

[0040] The present invention will be further described below by way of examples.

[0041] like Figure 1 and Figure 2 As shown, a battery system includes:

[0042] The bottom bracket device 1 is used to carry and connect the battery pack 4. The outer side of the battery pack 4 is connected and fixed with the skin component 3 through the skin bracket 2;

[0043] The base support device 1 is installed behind the vehicle cab, specifically on the upper side of the two main beams of the frame. It adopts connecting plates and bolts to ensure reliable and stable connection. The hollow area of the base support device 1 is used to connect and fix the battery pack 4. The battery pack 4 is connected and fixed to the four peripheral beams of the base support device 1 by bolts, spring washers and nuts, ensuring the stable connection between the battery pack 4 and the base support device 1, and ensuring mechanical reliability and sealing.

[0044] Further, such as Figure 1 、 Figure 3 and Figure 4As shown, the battery pack 4 includes several stacked battery packs, and the battery boxes 4.2 of all the battery packs are stacked in sequence. The adjacent battery boxes 4.2 are connected and fixed by fixing bolts 13, and the top battery box 4.2 is connected to the battery box cover 4.1; the battery pack 4 drives the vehicle's electric motor to rotate by storing electrical energy and releasing energy, thereby providing the driving force required by the vehicle.

[0045] The battery pack 4 adopts a stacking connection method of multiple battery packs, which can eliminate the battery box cover 4.1 of the battery pack and the fixed support beam structure of the traditional battery frame, which can effectively reduce the height dimension of the entire battery system, reduce the cost of the battery system, and improve the volume energy density of the system; in addition, the fixing bolts 13 connecting the battery box cover 4.1 and the battery box body 4.2 can be eliminated, and the number of fixing bolts 13 is halved, which can not only improve processing and manufacturing efficiency, but also reduce material costs.

[0046] When stacking battery packs, the guide structure allows for precise positioning and installation. This structure can utilize a matching guide pin and pin hole design. The pins attached to the battery packs can have inconsistent front and rear dimensions, preventing errors and improving production efficiency and assembly accuracy. The conductor structure is not limited to a matching guide pin and pin hole design; it can also utilize a matching block and slot design, as long as the battery packs are accurately stacked and installed.

[0047] Assuming that each battery pack layer requires 20 fixing bolts 13, a system consisting of four battery packs would require 80 fixing bolts 13. However, the battery pack stacking solution adopted in this application only requires 40 fixing bolts 13. Furthermore, the battery box cover 4.1 between each two battery packs is eliminated, and the crossbeams used to secure the battery packs in the battery system frame can also be eliminated. This can significantly reduce the overall weight of the battery system.

[0048] Further, such as Figure 5 and Figure 6 As shown, the fixing bolt 13 includes a threaded column 13.4, one end of the threaded column 13.4 is fixed with a bolt head 13.1, and the other end is threadedly connected to a lock nut 13.6. A flat washer 13.3 is sleeved on the end of the threaded column 13.4 close to the bolt head 13.1, and a flat washer 2 13.5 is sleeved on the end close to the lock nut 13.6. A spring washer 13.2 is sleeved on the threaded column 13.4 between the bolt head 13.1 and the flat washer 13.3.

[0049] The fixing bolt 13 adopts the form of bolt head 13.1 + spring washer 13.2 + flat washer 13.3 + flat washer 2 13.5 + anti-loosening nut 13.6. After the fixing bolt 13 is tightened according to the torque requirement, the spring washer 13.2 is elastically deformed to press against the bolt head 13.1, thereby increasing the contact area between flat washer 13.3, flat washer 2 13.5 and the battery box 4.2, increasing the friction force, improving the connection stability of the anti-loosening nut 13.6, and preventing the anti-loosening nut 13.6 from falling off; in addition, when subjected to vibration or impact, the spring washer 13.2 will undergo elastic deformation, absorb part of the energy and convert it into elastic potential energy, thereby reducing the loosening and vibration effects of the fixing bolt 13.

[0050] Furthermore, a sealing gasket is connected to the sealing surfaces surrounding the battery case 4.2. Double-sided adhesive tape is applied to one side of the sealing gasket, which is secured to the sealing surface of the battery case 4.2. This provides sealing, waterproofing, dustproofing, and cushioning, effectively preventing external impurities such as moisture and dust from invading the battery pack, thereby protecting the battery cells and the entire battery system. Furthermore, the sealing gasket exhibits excellent elasticity and cushioning properties, absorbing and dispersing resonance and impact generated during battery pack operation to a certain extent, reducing damage to the battery cells.

[0051] Furthermore, the bottom of the battery box 4.2 is provided with an insulation coating to reduce heat dissipation from the internal temperature of the battery pack, thereby improving product performance and effectively reducing the temperature drop rate of the battery pack. The insulation coating thickness is preferably at least 1.5mm, which can meet the requirements of operating under extreme ambient temperatures of -40°C to 65°C.

[0052] The skin bracket 2 can prevent the skin from being subjected to external impact during operation, which may cause damage to related internal electrical components. Furthermore, a skin is provided for each battery pack in the skin assembly 3, and the adjacent skin outer edges are overlapped and pressed more than 10 mm, and are reinforced and fixed by bolts. This can not only improve the sealing of the skin, but also prevent the overlapping parts from being crushed by the bolts, causing deformation and other problems; that is, the second layer of battery pack skin and the first layer of battery pack skin are fixedly connected by bolts in the flange edge area around them, and the base support device 1 is connected and fixed by tightening bolts.

[0053] Upper frame assembly 6, such as Figure 1 and Figure 2 As shown, it is connected and fixed above the base device 1, and is used to carry and connect the high-voltage distribution box 7, the BMS low-voltage control box 8 and the liquid cooling unit 5. The liquid cooling unit 5 is located on one side of the high-voltage distribution box 7, and the BMS low-voltage control box 8 is located below the high-voltage distribution box 7.

[0054] The upper frame assembly 6 is connected and fixed to the base device 1 and the battery pack 4 by means of bolts, spring washers and nuts. The high-voltage distribution box 7 and the BMS low-voltage control box 8 are arranged in the upper and lower layers, which can effectively save space and reduce the overall height of the battery system. The high-voltage distribution box 7 and the BMS low-voltage control box 8 are respectively connected and fixed to the crossbeam of the upper frame assembly 6 by fastening bolts, and the hydraulic unit is also fixed to the crossbeam of the upper frame assembly 6 by fastening bolts.

[0055] The upper frame assembly 6, the bottom support device 1, the battery pack 4, the high-voltage distribution box 7, the BMS low-voltage control box 8, and the liquid cooling unit 5 are interconnected and fixed, which can effectively ensure the connection reliability of the overall system and reduce or avoid the possibility of mechanical resonance.

[0056] The liquid cooling pipe assembly 9 is fixed to the base device 1 by using a pipe rack, one end of which is connected to the coolant inlet and outlet of the liquid cooling unit 5, and the other end of which is connected to the coolant inlet and outlet of the battery pack 4.

[0057] The high-voltage distribution box 7 is mounted on the upper frame assembly 6 and is connected and fixed by tightening bolts. Its function is to ensure the safety, insulation and electromagnetic interference shielding of the entire high-voltage system and various high-voltage electrical equipment.

[0058] The BMS low-voltage control box 8 is mainly used to manage the vehicle's high-voltage circuits. It is responsible for monitoring the working status of the battery pack 4 and ensuring the stable and safe transmission of electric energy to the motor. In addition, it can also intelligently adjust the current and voltage according to the actual needs of the vehicle, thereby optimizing the vehicle's performance and cruising range. It has overcurrent, overvoltage, undervoltage and other protection functions. Once an abnormal situation is detected, the BMS low-voltage control box 8 will immediately cut off the power supply to prevent the battery pack 4 from being damaged and ensure vehicle safety.

[0059] The liquid cooling pipe assembly 9 provides the required cooling water or hot water medium for the entire battery system. Furthermore, the cooling pipes connecting the liquid cooling pipe assembly 9 to each battery pack of the battery group 4 adopt a branch parallel connection method. The flow resistance of each battery pack is consistent, which reduces the power requirement of the liquid cooling unit 5 system and ensures temperature difference consistency. The two main coolant inlet and outlet pipes of the battery pack 4 are connected to the base device 1 using a pipe rack method and are fixed by tightening bolts.

[0060] The charging base 11 is connected and fixed to the bottom of the base device 1 to provide power to the battery pack 4;

[0061] The high-voltage power harness 12 is divided into two parts. One part of the high-voltage power harness 12 is connected to the battery pack 4 through the high-voltage distribution box 7, and the other part of the high-voltage power harness 12 is connected to the vehicle control box end through the high-voltage distribution box 7;

[0062] The high-voltage power harness 12 carries the voltage and high current of the entire battery system, and transmits the electrical energy of the battery pack 4 to the electric motor to realize the power output of the vehicle.

[0063] The low-voltage communication harness 10 is divided into two parts. One part of the low-voltage communication harness 10 is connected to each battery pack in the battery pack 4, and the other part of the low-voltage communication harness 10 is connected to the vehicle's low-voltage electrical equipment through the high-voltage distribution box 7 and the BMS low-voltage control box 8 to form a system communication circuit.

[0064] The low-voltage communication harness 10 transmits control signals to the BMS low-voltage control box 8 and provides power to other components of the battery system. The low-voltage communication harness 10 can be regarded as the "neural network" of the battery system, responsible for implementing conversion, detection and control signals to ensure the coordinated operation of various vehicle systems.

[0065] Furthermore, the high-voltage power harness 12 and the low-voltage communication harness 10 are both connected and fixed to the base device 1 using fixing clips in combination with cable ties to ensure the connection reliability of the high-voltage power harness 12 and the low-voltage communication harness 10.

Claims

1. A battery system, characterized in that: include: A bottom support device (1) is used for carrying and connecting a fixed battery pack (4), and a skin assembly (3) is connected and fixed to the outer side of the battery pack (4) via a skin bracket (2); The upper frame assembly (6) is connected and fixed above the bottom support device (1) and is used to carry and connect and fix the high-voltage distribution box (7), the BMS low-voltage control box (8) and the liquid cooling unit (5). The liquid cooling unit (5) is located on one side of the high-voltage distribution box (7), and the BMS low-voltage control box (8) is located below the high-voltage distribution box (7); The liquid cooling pipe assembly (9) is fixed to the base device (1) by using a pipe rack connection, one end of which is connected to the cooling liquid inlet and outlet of the liquid cooling unit (5), and the other end of which is connected to the cooling liquid inlet and outlet of the battery pack (4); A charging base (11) is connected and fixed below the base device (1) to provide power to the battery pack (4); A high-voltage power harness (12) is divided into two parts, one part of the high-voltage power harness (12) is connected to the battery pack (4) through the high-voltage distribution box (7), and the other part of the high-voltage power harness (12) is connected to the vehicle control box end through the high-voltage distribution box (7); The low-voltage communication harness (10) is divided into two parts. One part of the low-voltage communication harness (10) is connected to each battery pack in the battery pack (4), and the other part of the low-voltage communication harness (10) is connected to the low-voltage electrical equipment of the vehicle through the high-voltage distribution box (7) and the BMS low-voltage control box (8), thereby forming a system communication circuit.

2. A battery system according to claim 1, characterized in that: The battery pack (4) comprises a plurality of stacked battery packs, wherein the battery boxes (4.2) of all the battery packs are stacked in sequence, and adjacent battery boxes (4.2) are connected and fixed by fixing bolts (13), and a battery box cover (4.1) is connected to the top battery box (4.2).

3. A battery system according to claim 2, characterized in that: The fixing bolt (13) comprises a threaded column (13.4), one end of the threaded column (13.4) is fixed with a bolt head (13.1), and the other end is threadedly connected with a locking nut (13.6), one end of the threaded column (13.4) close to the bolt head (13.1) is sleeved with a flat washer (13.3), and one end close to the locking nut (13.6) is sleeved with a flat washer (13.5), and a spring washer (13.2) is sleeved between the bolt head (13.1) and the flat washer (13.3) on the threaded column (13.4).

4. A battery system according to claim 2 or 3, characterized in that: Sealing pads are connected to the sealing surfaces around the battery box (4.2).

5. A battery system according to claim 2 or 3, characterized in that: The bottom of the battery box (4.2) is provided with a heat-insulating coating.

6. A battery system according to claim 1 or 2, characterized in that: The cooling pipelines connecting the liquid cooling pipeline assembly and each battery pack of the battery group (4) adopt a branch parallel connection mode.

7. A battery system according to claim 1 or 2, characterized in that: A skin is provided corresponding to each battery pack in the skin assembly (3), and adjacent skins are pressed against each other and reinforced and fixed by bolts.

8. A battery system according to claim 1 or 2, characterized in that: The high-voltage power harness (12) and the low-voltage communication harness (10) are both connected and fixed to the base support device (1) using a fixing clip in conjunction with a cable tie.

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